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Handmade Glass Marbles | ||
Sulphides
Sulphide marbles are of clear glass with silvery figures inside made
between 1850 to 1910 in the East German province of Thuringen. There
is a possiblity of suphide marble production in the United Staes because
many decanters and water glasses were made in America containing sulphide
heads and other figures. Many such pieces of glassware were produced by
Bakewell Pears and Company in Pittsburgh. Figures inside the marbles
were of china clay, gypsum, kaolin, or similar materials. The clay was
placed into double form molds and dried slowly in a kiln at twenty-five
degrees Centigrade. The silvery appearance is an effect of a small air
layer between it and the crystalline glass which surrounds it.
Sulphides have a great variety of figures inside, the major types including wild and domestic mammals and birds, figures of people, numbers, religious figures, and other animals as fish, reptiles, and amphibians. The most common of the figures are the domestic animals, especially dogs, chickens, and sheep, as well as some wild animals as lions, bears, and rabbits. Other figures range from fairly common to unique. Unusual figures include pocket watches, drums, cannons, rocking horses, and a colored full-rigged sailing ship. It is unusual to find sulphides with two figures inside because of the difficulty in manufacturing them.
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Song: "It's A Small World"
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There are two different methods which could be used to insert the figure
into the glass. One called for the heating of one end of a glass rod
by one workman, while another glassworker pressed the figure into this
soft glass. Then the glass at the bottom of the rod was folded toward
the center entirely enclosing the figure, then cut with the marble
scissors. The second process, quite similar to the first, involved
placing the figure on top of a mass of soft glass with the glass folded
around the figure. A small air space between the figure and the glass
reflects light rays giving the silvered effect. The best silver
appearance occurs when the figure has a porous surface. 
The glass and figure both have to be heated to a certain temperature
before the figure may be inserted into the glass. Glass was too hot
might cause the figure to break, while a figure too hot could expand
and break the marble or lose much of its silvery luster. Bubbles
developed around the figures if they were too porous, perhaps obscuring
the figure. Smoke residue remaining in the figures, from their stay in
the kiln, or if not heated to the correct temperature before insertion
into the glass, will create the same effect. After formed, sulphides
were put into an iron pot in an annealing oven where the cooling process
took place. The marbles remained in the pot after removal from the oven
until they had cooled completely. While still warm, sulphides had to be
protected from air currents which could cause the glass to crack,
especially larger marbles.